Picker stick checking mechanism



y 7, 1969 E. L. HOWELL 3,446,253

PICKER STICK CHECKING MECHANISM Filed March 16. 1966 FIG-l FIG-2 I 7 /8 X a I9 INVENTOR. EMORY L. HOWELL ATTORNEY United States Patent 3,446,253 PICKER STICK CHECKING MECHANISM Emory L. Howell, Greenville, S.C., assignor to Dayco Corporation, Dayton, Ohio, a corporation of Delaware Filed Mar. 16, 1966, Ser. No. 534,866 Int. Cl. D0311 49/40, 49/36 US. Cl. 139-161 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a picker stick checking mechanism for shuttle type looms, and also relates to check straps which are a part of such a mechanism. Mechanisms of this type primarily consist of one or more endless check straps which are mounted on a portion of the mechanism which in turn is mounted on a portion of the loom. The check straps are designed to surround the picker stick so that when the stick is moved forward by its mechanism to strike the shuttle, the inner end of the stick strikes an inner portion of the straps which check the movement of the stick. A similar action occurs when the picker receives the shuttle on its return passage, the momentum causing the picker and stick to travel in the opposite direction where the outer side of the stick is caught at a dilferent inner portion of the check straps. Thus the picker stick is partially checked in both directions by the action of the straps, and this is accomplished in a gradual manner by permitting these straps to slide along their retaining mechanism in order to gradually dissipate the kinetic energy which has been built up during this action. It is obvious, of course, that these straps undergo a terrific amount of wear due to the friction, as well as the heat which is built up.

In conventional checking mechanisms utilizing multiple straps, it is necessary to replace these straps frequently because of the wear which takes place. Further, the conventional strap is affected by high temperatures which tend to break down their internal structure rather rapidly, and thus conventional straps are also affected by humidity which further tends to deteriorate them. An additional reason for frequent replacement of the straps lies in the fact that texture and composition of these straps varies considerably, so that each strap fails to play an equal part in taking up the impact of the stick. Such a conventional mechanism is found in United States Patents Nos. 2,426,353, 2,775,264, and 2,783,779, all of which illustrates the use of rubberized fabric straps of equal length.

Applicant has overcome many of the undesirable properties of the checking mechanisms by utilizing a rigid plastic material, such as high molecular weight polyethylene, to provide multiple check straps, since this material has been found to overcome the inherent disadvantages of the conventional straps. These straps will be mounted somewhat similarly to those in the prior art, except, however, that the uppermost of these straps has each of the straps when the picker stick is caught, while the intermediate ones are graduated proportionately therebetween. This permits equal distribution of the forces upon each of the straps when the picker stick is caught. while the sliding motion of the strap is also equal so that the same relationship is maintained when the stick is caught in the other direction.

It is a principal object of the present invention, therefore, to provide an improved checking mechanism for equalizing wear on the individual straps.

It is a further object to provide check straps which are relatively unafi'ected by high temperatures and humidity.

It is another object to provide a mechanism whereby all check straps will slide equally within their retained mechanism to improve the picker stick holding characteristics.

The invention is more fully described in the accompanying specification and drawings, in which:

FIGURE 1 is a side elevational view of the novel checking mechanism.

FIGURE 2 is a section taken along lines 22 of FIG- URE 1.

FIGURE 3 is a sectional view illustrating a portion of the mechanism of FIGURE 1.

Turning now to the drawings, reference numeral 11 represents a portion of the loom known as the lay, upon which the shuttle travels. Vertically mounted on the lay in a series of brackets 12, 13, 14, and 15, which are supported by means of a conventional fastening member such as nut 16 which also serves to permit vertical adjustment of the mechanism. Mounted within the supporting members are check straps 17, 18, 19, and 20 which are rigid endless members, as shown in FIGURE 2. These straps are formed of rigid plastic materials such as high molecular weight polyethylene which is understood to mean polyethylene having a molecular weight of about 600,000 or greater. The uppermost of these straps 17 has a greater circumference than the next lower strap 18; which in turn has a greater circumference than the next lower strap 19; which in turn has a greater circumference than the lowermost strap 20. Each of these straps has a constant taper as shown in FIGURES 1 and 3, this taper being parallel to the picker stick at rest in order that the stick may contact the inner surfaces of all straps equally. This provides for an equal absorption of the built-up energy. In addition, each of the stick-contacting portions is thicker, as designated by portion 25, to aid in absorbing this energy.

The picker stick 21, upon which is mounted the picker 22, is shown in FIGURE 1 in solid lines at the left-hand side of its travel, which is in its position just after catching the shuttle and just before throwing it on its return journey. The phantom lines in FIGURE 1 illustrate the position of the stick and picker after it has thrown the shuttle to the right and while it is awaiting the return throw of the shuttle. The picker stick, therefore, contacts the check strap at its outer surface 23 or its inner surface 24, these terms outer and inner referring to the position of the picker stick and mechanism with respect to each side of the loom.

When the stick is in the right-hand position of FIG URE 1 and is struck by the returning shuttle, the momentum drives the stick outwardly, or to the left, until the outer surface 23 of the stick contacts the inner surface of the straps 17, 18, 19, and 20. Since these straps are retained but not tightly held 'by the members 12 to 15, they are allowed to slide with the travel in order to gradually ease the shock of impact. Because of the different circumferences of the straps as shown, each of the straps will be contacted simultaneously equally and will slide equally thus distributing the impact equally among the straps.

Similarly, as the picker stick is actuated inwardly or to the right in FIGURE 1, it is caught at the end of its stroke or its inner surface 24 by the other end of the straps 17, 18, 19, and 20 for equal distribution of the impact, while the straps are also free to slide along the restraining members to help dissipate the impact.

By using a rigid plastic material such as high molecular weight polyethylene, the inherent weaknesses of rubberized fabric are overcome, since the straps of the present invention are not affected by high temperature or humidity conditions which are ordinarily present during operation. This eliminates the necessity for continuous adjustment of the various straps which is necessary when conventional materials are used. This improvement is enhanced by the fact that rigid plastic check straps have uniform characteristics to a degree not found in conventional rubberized fabric straps.

The present inventor has found that the improved results provided by rigid plastic material is quite unexpected, since it has heretofore been thought by the users of looms that a flexible material such .as rubberized fabric was necessary to provide proper shock absorption. It was also believed by these users that a. rigid material would show inherent instability because of its refusal to flex and give under the impact. The present inventor has found that this is not the case because of the' unusual action of the rigid straps and their simultaneous sliding action in the mechanism when struck by the stick, and the combination of the mechanism which provides for all the straps to be of dissimilar circumferences as described.

It should be noted that applicant does not intend to limit his novel straps to the material referred to above; namely, high molecular weight polyethylene, but also intends that other materials having good friction characteristics and the ability to withstand moisture and high .temperatures may also be used and should be considered as full equivalents. Other modifications may be made in this specific mechanism without department from the spirit of the invention.

What is claimed is:

1. In a loom having a picker stick, a picker stick checking mechanism comprising a plurality of rigid endless check straps mounted on said "loom in superimposed relationship, each of said straps having a different circumference, said picker stick simultaneously contacting all of said straps.

2. The mechanism of claim 1 in which the uppermost of said straps has a greater circumference than the lowermost of said straps.

3. The mechanism of claim 1 in which said straps have a constant taper.

4. The mechanism of claim -1 in which all of said straps have a constant taper which is parallel to said picker stick when contacting said straps.

5. The mechanism of claim '1 in which said straps have a thicker wall at their picker stick contacting portions than their remaining portions.

6. The mechanism of claim .1 in which said straps are composed of high molecular weight polyethylene.

7. The mechanism of claim 1 in which said straps are composed of high molecular weight polyethylene and have a constant taper which is parallel to said picker stick when contacting said straps, said straps having a thicker wall at their picker stick contacting portions than their remaining portions.

References Cited UNITED STATES PATENTS 3,329,175 7/1967 Ayers et al 139-164 2,997,072 8/1961 Messer 139161 3,282,302 11/1966 Messer 139-161 2,426,353 8/ 1947 Johnson 139--165 2,509,676 5/1950 Dickinson 139-165 3,003,523 10/1961 Cronic 139--165 FOREIGN PATENTS 567,192 10/ 8' Belgium. 978,052 12/ 1964 Great Britain.

OTHER REFERENCES Textile Industries, vol. 127, No. 2, February 1963, pp. 36-37.

JAMES KEE CHI, Primary Examiner.

P0405" UNITED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION Patent No. ,44 53 Dated May 27, 1969 Inventor(s) Emory L. Howell It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Page 1, column 1, line 65 which presently reads "each of the straps when the picker stick is caught, while" should read a longer circumference than the lowermost straps, while mun EU Fuw SEALED DEC 2 3 m9 (SEAL) Attcst:

EdwuaMFlmherk WILLIAM E. soHuYLER, JR. Attesting Officer Commissioner of Patents 

